CPCB no longer sharing hourly air quality data

The Central Pollution Control Board (CPCB) has stopped sharing Delhi’s hourly Air Quality Index (AQI) through the Sameer app, two weeks after it first began sharing it. It was not immediately clear why the step was taken.

CPCB began sharing the hourly AQI data for iOS users on the app from November 19, but the feature has not been available since Wednesday. Till it was stopped, iOS users could see both the hourly average AQI and the 24-hour rolling average.

The change in the 24-hour AQI is generally gradual and is used to sum up how air quality has improved or deteriorated over a day. The hourly AQI shows a more immediately reading, allowing people to make informed decisions.

For instance, on Tuesday, when hourly data was last available, Delhi’s average AQI was 358 (very poor) at 8am — indicating it was a bad time to step out. This, in comparison, was 150 (moderate) at 4pm and 141 (moderate) at 6pm, indicating presence of fewer pollutants in the air.

When contacted, CPCB did not respond to HT’s queries about the reason behind not sharing the hourly AQI data.

Sunil Dahiya, analyst at Centre for Research on Energy and Clean Air (CREA), said that for an individual, the hourly AQI is more important, as it explains real-time exposure.

“If one has to make an informed decision on whether to exercise or step out, the hourly AQI is needed. It is important to have transparency and this data to be made readily available to the public. At the same time, it is important to create awareness around the app and educate people on how it can help them understand the prevailing air quality better.”